locke in past and present?

this episode continually flips back from past to present but i thought that there was a definite distinction between to two. when locke takes ben and richard on the walk he ends up taking them to the plane that crashed on the island and was filled with heroine. he sounds like he is talking crazy when he tells richard that a man is about to come out of the forest and he will need to heal his gunshot wound and tell him that he needs to die in order to get everyone back on the island. halfway through his story i realize that locke is talking about himself. and just as i realize this locke (in the past..which is confusing) comes out of the jungle just like he predicted. what i dont understand is how he knew this would happen right then and how he went back in time.

in the past daniels mom is preparing to take jack and kate to the dharma initiative to deal with the bomb. hopefully by the time they get back to the camp everyone will have evacuated so they can take care of what they need to do. dr chang, miles dad, finally believes what faraday said to him about being from the future and everyone needing to get off the island. hopefully he will get everyone to evacuate and everything will work out as planned. it also makes me excited that dr chang knows miles is actually his son. im sure that they will have a hard time getting people to evacuate the island and an even harder time getting people to believe them.